基于双子代数的高通量筛选系统优化控制

为了提高控制效率,对一类新兴的离散事件系统,即高通量筛选系统,利用双子代数dioid同时从事件域和时间域进行建模.对于很多离散事件系统,期望的输入输出模型行为是进行优化控制时常用的指标.然而,根据实际控制要求,往往高通量筛选系统的优化指标还会考虑期望的状态轨迹或期望的输出轨迹.对此,研究dioid框架下具有不同优化指标的优化控制结构,并结合状态反馈和输出反馈进行讨论.最后通过实例说明了应用该控制结构的方法.仿真结果表明了所提出的优化控制方法的有效性.     

不确定控制系统的输出反馈镇定

本文研究具有匹配和非匹配不确定性系统的输出反馈镇定。在对不确定性的增长性作适当限制的条件下，利用本文引入输出反馈严格正实系统的概念，构造了保证团环系统在开球Ｂ上或在Ｒ＾ｎ上指数式稳定的光滑或解析输出反馈控制律。     

非线性微分——代数系统的输出反馈镇定控制

对满足线性增长条件的非线性微分--代数系统, 研究了其输出反馈镇定控制问题. 通过将状态观测器与控制器耦合在一起设计, 构造出一种非初始化的线性高增益状态观测器, 具有良好的鲁棒性. 基于反推设计方法构造出一个线性的动态输出补偿器, 使得整个闭环系统是渐近稳定的. 仿真结果验证了本文所提控制方法的有效性.     

高通量筛选系统的双子代数建模

对一类新兴的离散事件系统—–高通量筛选系统而言,max-plus算法是强有力的事件域建模与分析工具,因此,其常被用来进行该系统的建模及控制.然而,有时,尤其是在执行控制策略的时候,需要时间域的描述.为了同时从时间域和事件域高效描述系统,本文利用基于双变量的形式幂级数,把max-plus算法模型扩展为双子代数模型.对可能产生的非因果模型,为便于进行系统分析、仿真和后续的控制,提出了多个相应的基于双变量(时间变量和事件变量)的转换矩阵.通过矩阵转换,得到满足要求的因果模型.最后用实例表明了该方法及其在提高该系统控制效率方面的有效性.     

一类不确定时滞广义系统的保性能控制

针对一类具有状态时滞的不确定广义系统考虑其保性能控制问题.利用Lyapunov稳定性理论,采用线性矩阵不等式处理方法,提出了静态输出反馈情况下的保性能鲁棒控制器的存在条件和设计方法,保证了对所有允许的不确定性,闭环系统是稳定的,而且给出相应情况下的性能指标上界.最后举例说明该方法的正确性.     

Buck型变换器输出跟踪的自适应动态规划算法

本文采用自适应动态规划算法研究了Buck型DC–DC变换器系统的输出跟踪问题.首先构造一个误差系统,并定义含跟踪误差和控制代价的性能指标;然后,利用自适应动态规划算法得到Buck型变换器系统的最优控制,使得含有跟踪误差和控制代价的性能指标达到最优.接着,利用该算法研究了网络环境下的Buck型DC–DC变换器系统的输出跟踪问题.该算法避免了代数求解Riccati方程,求解简洁快速.最后,仿真实验验证了该算法的有效性.     

非线性微分-代数系统的输出反馈镇定:基于线性采样控制

对满足指数1和线性增长条件的非线性微分-代数系统,本文证明其采样输出反馈镇 定控制问题可解.首先,给出一个线性显式非初始化状态观测器设计;然后,构造出线性的采样输出 反馈控制器,使得整个闭环系统渐近稳定.仿真结果表明了所提控制方法的有效性.     

含有不确定性的非线性互联系统的鲁棒分散H_∞控制(英文)

讨论了含有不确定性非线性互联系统的鲁棒分散H∞ 控制问题 ,建立了鲁棒H∞ 控制与H∞ 控制之间的联系 .在这种联系基础上 ,基于Hamilton Jacobi不等式给出了含有不确定性互联系统的鲁棒分散H∞ 控制问题存在的充分条件 .分别构造出状态反馈和输出反馈分散控制器以确保闭环系统从外部干扰输入到控制输出的L2 增益小于或等于一预先给定的正数 .     

基于观测器的广义时滞系统弹性保成本控制

在同时考虑系统矩阵参数不确定性和控制器不确定性对系统性能影响的前提下,研究了一类基于观测器的不确定广义时滞系统的弹性保成本控制问题.基于Lvapunov稳定性理论,通过构造广义Lyapunov函数和广义二次性能指标函数,以线性矩阵不等式的形式给出了基于观测器状态反馈的弹性保成本控制器的设计方法.该控制器不仅保证了广义时滞系统是鲁棒稳定而且使其具有相应的性能指标上界.采用一种新方法将系统弹性保成本控制器设计和状态观测器增益矩阵求取转化为两组严格线性矩阵不等式的可行解问题.最后通过算例验证了该方法的可行性和有效性.     

不确定离散切换系统具有极点约束的保性能控制

对一类含有范数有界不确定性的离散切换系统和一个二次型性能指标,研究其具有闭环极点约束的鲁棒状态反馈保性能控制问题．利用二次Lyapunov函数方法和线性矩阵不等式技术,给出了鲁棒保性能控制器存在的一个充分条件,在所构造切换规则下,闭环系统二次D稳定,且满足给定的性能指标．在此基础上,将次优保性能控制器设计问题转化为一组线性矩阵不等式约束下的凸优化问题．数值例子说明了所提方法的有效性．     

Optimal behaviour prediction using a primitive-based data-driven model-free iterative learning control approach

This paper suggests an optimal behaviour prediction mechanism for Multi Input-Multi Output control systems in a hierarchical control system structure, using previously learned solutions to simple tasks called primitives. The optimality of the behaviour is formulated as a reference trajectory tracking problem. The primitives are stored in a library of pairs of reference input/controlled output signals. The reference input primitives are optimized at the higher hierarchical level in a model-free iterative learning control (MFILC) framework without using knowledge of the controlled process. Learning of the reference input primitives is performed in a reduced subspace using radial basis functions for approximations. The convergence of the MFILC learning scheme is achieved via a Virtual Reference Feedback Tuning design of the feedback controllers in the lower level feedback control loops. The new complex trajectories to be tracked are decomposed into the output primitives regarded as basis functions. Next, the optimal reference input fed to the control system in order to track the desired new trajectory is then recomposed from the reference input primitives. The efficiency of this approach is demonstrated on a case study concerning the control of a two-axis positioning mechanism, and the experimental validation is offered.     

Adaptive stabilization of uncertain nonholonomic systems by output feedback

The adaptive output feedback control strategy is presented for a class of nonholonomic systems in chained form with nonlinearity uncertainties. A new observer and a filter are introduced for the states and parameter estimation. The proposed control strategies guarantee the convergence of the closed-loop system. The simulation example demonstrates the efficiency of the proposed method.     

Non-fragile positive real control for uncertain linear neutral delay systems

This paper is concerned with the problem of non-fragile positive real control for uncertain neutral delay systems with time-invariant norm-bounded parameter uncertainty. Time delays are assumed to appear in both the state and the controlled output equations. The state feedback gains are with norm-bounded controller uncertainties. For both the cases with additive and multiplicative controller uncertainties, we address the problem of designing memoryless state feedback controllers such that, for all admissible uncertainties, the resulting closed-loop system is stable and the closed-loop transfer function is extended strictly positive real. Sufficient conditions for the existence of desired controllers are given in terms of linear matrix inequalities (LMIs). When these LMIs are feasible, the expected memoryless state feedback controller can be easily constructed via convex optimization. An illustrative example is given to demonstrate the validity and applicability of the proposed approach.     

Decay rate constrained stabilization of positive systems using static output feedback

This paper investigates the stabilization problem by means of a static output feedback control for positive systems with/without interval uncertainties. The designed closed‐loop system is ensured to be positive and stable with a prescribed decay rate. Necessary and sufficient conditions for the existence of such controllers are established in terms of linear matrix inequalities together with a matrix equality constraint. Furthermore, the desired static output feedback controllers can be derived directly via the cone complementarity linearization techniques. Finally, an illustrative example is presented to show the validity of results obtained in this paper. Copyright © 2010 John Wiley & Sons, Ltd.     

Semi-global sampled-data output feedback disturbance rejection control for a class of uncertain nonlinear systems

This paper investigates the semi-global output feedback disturbance rejection control problem for a class of uncertain nonlinear systems with additive disturbances using linear sampled-data control. Aiming to reject the adverse effects caused by the uncertainties and unknown nonlinear perturbations which may not satisfy the strict feedback or feedforward structure, a new generalised discrete-time extended state observer is proposed to estimate the disturbance at sampling points. An output feedback disturbance rejection control law is then constructed in a sampled-data form which facilitates digital implementations. By selecting adequate control gains and a sufficiently small sampling period to restrain the state growth under a zero-order-hold input, the semi-global asymptotic stability of the hybrid closed-loop system and the disturbance rejection ability are proved. Both numerical example and an application of a single-link robot arm system demonstrate the feasibility and efficacy of the proposed method.     

随机型不确定中立时滞系统的鲁棒H∞控制

研究了一类具有不确定性的随机性中立时滞系统的鲁棒H∞状态反馈控制器的设计问题.假设时滞是已知的,且时滞同时出现在状态变量和控制变量中,利用线性矩阵不等式方法,给出了状态反馈控制器存在的时滞依赖的充分条件,保证了对于所有的参数不确定性,闭环系统是指数均方稳定的,且从干扰输入到被控输出的影响小于一个指定的性能指标.仿真算例验证了该方法的可行性.     

Modeling and control of high-throughput screening systems

In previous work it has been shown how a max-plus algebraic model can be derived for cyclically operated high-throughput screening systems and how such a model can be used to design a controller to handle unexpected deviations from the predetermined cyclic operation during run-time. In this paper, this approach is extended by modeling the system in a general dioid algebraic setting. Then a feedback controller can be computed using residuation theory. The resulting control strategy is optimal in the sense of the just-in-time criterion, which is very common in scheduling practice.     

output feedback control for uncertain stochastic systems with time-varying delays

This paper deals with the problem of H_∞ output feedback control for uncertain stochastic systems with time-varying delays. The parameter uncertainties are assumed to be time-varying norm-bounded. The aim is the design of a full-order dynamic output feedback controller ensuring robust exponential mean-square stability and a prescribed H_∞ performance level for the resulting closed-loop system, irrespective of the uncertainties. A sufficient condition for the existence of such an output feedback controller is obtained and the expression of desired controllers is given.     

结构不确定离散系统的最优非脆弱保成本控制

讨论了一类不确定线性离散系统的最优非脆弱保成本控制问题.考虑的系统和状态反馈控制器均具有时变的结构化的不确定性.基于线性矩阵不等式的方法,给出了存在和设计非脆弱保成本控制律的一个充分条件,以及在使二次成本函数上界最小意义下,最优非脆弱保成本控制律的凸优化设计方法.并用数值例子说明该方法降低了成本函数上界的保守性.